When you send out emails know who you want to open them, and make sure the content you're sending out provides value to that specific target group.
Lasting relationships with relevant bloggers & journalists mean you may never have to spend a dime on marketing.
Low barriers to entry combined with the ease of new platforms in setting up a blog make this a no-brainer first step in your content marketing plan.
Understand what your content marketing goals are. Without knowing your goals, how will you be able to determine whether or not your content marketing efforts are successful? Develop KPI's to ensure you are seeing a return on your investment.